1888 Sporter marked 7.7mm

[RustyReel]

I've been reading with interest the recent thread on the 1888 Commission rifle. Other than diverting that conversation I'm posting my question here.

I have an 1888 Sporter that has a Krupp barrel stamped 7.7mm. Any idea what that translates to? I assumed .318 but I have not slugged the bore (I know, do it?) I've posted a pic of the rifle on the site before, so just posting the making in question here. Thanks in advance!

[Kraschenbirn]

.303 Brit? I've frequently seen 7.7mm listed as the metric equivalent for .303 in descriptions of UK military weapons; most notably the Vickers MGs used early WWII aircraft.

Bill

[Der Gebirgsjager]

Also a designation for a WW II Japanese cartridge, 7.7mm Japanese, itself similar to the .303 British round, so you probably have a .311" bore. The question is, in what cartridge case? You may need to make a chamber cast to discover the answer.

DG

[RustyReel]

I haven't done a lot of work with this rifle but it is in caliber 8x57. I fired the RCBS 32-170 tumble lubed as cast at .320 and it shot into 5.5" at 50 yds. Because of the 7.7 marking I tried the Lee 312-185-R PC'd up to .315/.316 and they all tumbled at 50 yds. I then tried the RCBS boolit again PC'd up to .324 and shot a 50 yard ten shot group of 2.5". Given open sights and aging eyes I don't think that is too bad. Haven't tried to duplicate it. No pressure signs on the brass with any of the boolits.

I've owned and handled a bunch of 8mm Mausers and they were all stamped 7.9 or 7.92. Just wondering if there was/is any significance to the 7.7 marking. Curious.

[swheeler]

Rusty, 7.7mm = .303, therefore if you have a .318 groove your riflings are approx .0075 inches deep. It would be nice to know what a slug shows for groove diameter, and a slug of the throat, you know it is atleast .324+.

[swheeler]

and the color case on receiver is sweet!

[Larry Gibson]

Best to do a chamber cast to get dimensions as there were numerous rimmed and rimless cartridge monikered "7.7" chambered in German sporting rifles. More than likely it's a .318 groove diameter as that was common. No way to really know w/o making the chamber cast.

[john.k]

It may also be stamped to get around laws against military calibers.....For instance in 1904 ,India banned all military caliber guns ,having previously banned 577/450 and 7mm Mauser,so makers and retailers got around it by slightly modifying cartridges and markings ....note ,the whole of British East Africa and South Africa was administered from Delhi ,so the ban extended to the best safari regions......Westley Richards 318 Accelerated Express was just a 8x57 .

[swheeler]

It may also be stamped to get around laws against military calibers.....For instance .in 1904 ,India banned all military caliber guns ,so makers and retailers got around it by slightly modifying cartridges and markings ....note ,the whole of British East Africa and South Africa was administered from Delhi ,so the ban extended to the best safari regions.

That does make a lot of sense. We know RustyReel is shooting 8x57 with a cast bullet at .324 and good accuracy, .320 sucks big time from his accuracy notes so it's a 8x57S. I still would slug it though.

[swheeler]

RustyReel: I think we all need to see a couple pictures of the rifle all together, bet it is a beaut!

[RustyReel]

RustyReel: I think we all need to see a couple pictures of the rifle all together, bet it is a beaut!

Sadly I have not taken any decent pictures of the rifle. Here are a couple from the site where I got it. Most of you guys will probably recognize the background. No refresh necessary on this one, all I did was clean the bore and oil it a bit. I like this rifle and I know I should slug the bore/barrel but I just hate the thought of pounding a slug down the barrel!

[Larry Gibson]

"hate the thought of pounding a slug down the barrel!"

Exactly why I would do a cerrosafe cast of the chamber, throat and leade.

[swheeler]

Oh my my that makes me drewl down my chin, XXX gun porn!

[Drm50]

Isnt 7.9mm the actual cartridge we call 8x57 mm Mauser? Then the .318”/ .323” bore differences.
I would guess rifle uses 8x57 brass. The .311” bullets used in .303 Brit, 7.65 Mauser and 7.7 Jap are probably going to be undersize for bore.

[Texas by God]

I'd sit under a tree for hours staring at that rifle - occasionally looking up to see if a deer comes by.

Sent from my SM-A716U using Tapatalk

[sharps4590]

swheeler is right. The odds of that being a 303 Brit or anything else other than the 8 X 57J are probably just a little less than me winning the Power Ball lottery. Given my experience with old German rifles I'd still slug the bore and cast the chamber. Anything done to the rifle over here probably wouldn't have been reflected. I have 4 or 5 that were re-chambered to American cartridges or cartridges based on an American head size which whoever did the work conveniently chose not to indicate. Later S bore rifles were usually stamped "7,8"

Stunning rifle. It's one of the few early German bolt sporters not in my safe. Do you have the clips?

[swheeler]

sharps4590, I and several thousand other members would love to see some more German sporters, never get tired of them, works of art each one.

[sharps4590]

That they are sw, that they are! I'd be happy to post some pictures but I don not have a photo host and, after the debacle with photojunket, I'm not bothering to get one. I would be happy to e-mail some pictures and someone else has my permission to post them.

Rusty, you reckon a soft, lead slug driven down the barrel is going to put more stress on that barrel than all the jacketed loads it's seen in well over 100 years? If so, that's absurd.

[swheeler]

Here are some pictures of sharps4590 German rifles as promised, each and everyone is a work of art!


Top is a 98 Wilhelm Brenneke in caliber 7x64 Brenneke, lower is 88 Haenal-Rasch in cal. 9x57


Next is a Single shot Fredrich Jacob Bartles, built on an Ideal action in cal 8.15x46R with .318 groove dia.


Now a Shceutzen first model Haenel-Aydt in 8.15x46R with .312 groove dia.

[swheeler]

I just found out through the Ancestry website that sharps4590 and I are long lost brothers. With this new information available I am hoping that the 98 Brenneke will be willed to me! Hope